Harbour seals observed in the Wadden Sea area are dependent on the North Sea coastal and adjacent offshore areas where they feed and spend most of their time. Seals are, however, difficult to observe or count at sea, whereas accurate counts can be done when they haul out on the sandbanks of the Wadden Sea to rest, moult and breed. To obtain an indication of the status of the population observed in the Wadden Sea, counts of harbour seals and pups hauled out in the entire Wadden Sea area (including Helgoland), are coordinated between the three Wadden Sea countries, Denmark, Germany, and the Netherlands.